/**
 * Copyright 2019 The JoyQueue Authors.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.joyqueue.broker.config.scan;

import java.io.IOException;
import java.util.Set;

/**
 * @author jiangnan53
 */
public class ScannerExecutor implements Scanner {
    private static volatile ScannerExecutor INSTANCE;

    @Override
    public Set<Class<?>> search(String pkgName) throws ClassNotFoundException, IOException {
        Scanner fileScanner = new FileScanner();
        Set<Class<?>> fileSearch = fileScanner.search(pkgName);
        Scanner jarScanner = new JarScanner();
        Set<Class<?>> jarSearch = jarScanner.search(pkgName);
        fileSearch.addAll(jarSearch);
        return fileSearch;
    }

    private ScannerExecutor() {
    }

    public static ScannerExecutor getInstance() {
        if (INSTANCE == null) {
            synchronized (ScannerExecutor.class) {
                if (INSTANCE == null) {
                    INSTANCE = new ScannerExecutor();
                }
            }
        }
        return INSTANCE;
    }
}
